Abstract

The Regional Variety Trials (RVT’s) Series 3 Phase 2 Hort Innovation project aims to evaluate 20 CSIRO breeding lines with industry standards (344, 268, 741, 816 and A16) and five Hidden Valley Plantation bred selections in a range of sites around Queensland and New South Wales. In this project we measured yield, kernel quality and tree performance to ultimately release new varieties to the macadamia industry. Initially, ten sites were planted in 2008 between Macksville in NSW and Mackay in central QLD. Two of those sites have now been abandoned because of management issues and change of ownership. Acacia Plateau near Casino in NSW was decommissioned in 2011 and McLean’s Ridges at the end of 2014, the latter is still being farmed by the new owner under a Material Transfer Agreement. The remaining eight sites include Mackay and Emerald in the north, Childers, Bundy Sugar, Decortes and Booyan in the Bundaberg region, and Macksville and Alstonville in NSW. In 2014, Wirrawilla near Bundaberg, was included in the project. This site was previously an Abnormal Vertical Growth (AVG) trial site that included all the test and standard varieties. In November 2015 the Childers site was devastated by a storm and will not be assessed from 2015 on. All sites have 180 trees with six reps of each variety except for Childers with 120 trees, and Wirrawilla with 160 trees. Trees are strip harvested to year six and harvested five times in years seven, eight and nine. At harvest four, nuts are collected from the ground and bagged, remaining nuts in the tree are stripped out and bagged separately, effectively making harvest five.All nuts from all trees are bagged at each harvest, weighed and then sampled. The nuts are dehusked and weighed again before oven drying to 1.5% moisture content. Individual tree yields are calculated from the sampling process. Samples are stored in air tight barrels at 4C for kernel assessment at the end of the season. Tree heights and widths are measured at each site each year.In this project yield, kernel quality and tree performance were measured. More in-depth studies determined tree susceptibility to insects and pathogens, Abnormal Vertical Growth (AVG), kernel oil profiles and macadamia shelf life to ultimately make decisions on releasing new varieties to the macadamia industry.Four new macadamia varieties have been selected in consultation with the Macadamia Industry Variety Improvement Committee (MIVIC) and commercialised by the Department of Agriculture and Fisheries (DAF) from the CSIRO group of 20 while a further four varieties are being commercialised by HVP. The four DAF varieties are currently known as:MIV1-G. A large, precocious tree with high yields and kernel recovery (KR) of 40%+. Suitable for Bundaberg and Northern Rivers.MIV1-P. A small to medium, precocious tree suitable for high density planting. More suitable to Bundaberg but produces heavy crops in NSW. KR in the high 30’s.MIV1-J. Medium to large tree with large nuts and high KR (44%) more suited to the Bundaberg region.MIV1-R. Medium size tree that crops well in northern NSW with a KR of 37%.